1. Field of the Invention
The present invention relates to a television set with a satellite broadcast (BS) receiver, and more particularly to such a television set which has means for displaying a BS converter power supply condition.
2. Description of the Prior Art
Recently, satellite broadcasting has been finding widespread use. FIG. 1A shows one conventional satellite broadcast receiver. A satellite broadcast signal in a frequency range of 12 GHz transmitted by a satellite is received by a BS antenna 1 such as a parabola antenna which is erected outdoors. The satellite broadcast signal received by the antenna 1 is converted into a BS-IF signal, in a frequency range from 1 to 1.3 GHz by a BS converter 10, and the BS-IF signal is supplied through a coaxial cable 9 to a BS tuner 27 which is positioned indoors. In the BS tuner 27, a desired satellite broadcast channel is selected from the BS-IF signal and demodulated into a video signal and an audio signal, which are then supplied to an AV (audio/video) television set (hereinafter referred to as "AVTV") 30. The viewer of the AVTV 30 can now see video images and sounds selected by the BS tuner 27 on the AVTV 30.
The BS converter 10 does not have a rectifier circuit and a power supply transformer unlike a conventional power supply system such as a booster or the like, but is supplied with a DC voltage of 15 V from the BS tuner 27 for operation. The BS converter 10 with such a power supply system is reduced in size and weight, can easily be mounted on the BS antenna 1, and hence suffers less hum modulation. In the power supply system, the inner conductor of the coaxial cable 9 which interconnects the BS tuner 27 and the BS converter 10 is connected to the positive terminal of a power supply in the BS tuner 27, for supplying the voltage from the power supply to the BS converter 10.
The BS tuner 27 has on its back panel a manually operable selector switch for selectively supplying the DC voltage of 15 V from the power supply to the BS converter 10. The selector switch may select various modes depending on how the BS antenna 1 is connected to various devices. More specifically, the selector switch may be selectively shifted into "OFF", "ON" and "GANGED" positions. For example, as shown in FIG. 1A, when there is only one AVTV 30 and BS converter 10 is connected to only the tuner 27 as in usual home-use applications, the selector switch is shifted into the "GANGED" position. FIG. 1B shows an application in which programs broadcast from the satellite are viewed in different rooms at the same time. Specifically, in such an application, another BS tuner 27a and another AVTV 30a are added to the existing BS tuner 27 and AVTV 30. If the BS converter 10 were supplied with the power supply voltage from both the BS tuners 27, 27a through a distributor 29 and the coaxial cable 9, then the BS converter 10 might fail to operate properly. To avoid such a problem, the selector switch of the BS tuner 27a is shifted into the "OFF" position, and the selector switch of the BS tuner 27 is shifted into the "ON" position. Another power supply system for a BS converter that is shared by a plurality of BS converters is shown in FIG. 1C. The BS converter 10 on the BS antenna 1 which is erected on the roof of a building 31 is connected to wall terminals 33a, 33b, 33c, . . . coupled to the BS tuners 27, 27a, . . . through a distributor 29 and a booster 32. The BS converter 10 is supplied with a power supply voltage from the booster 32. Therefore, the selector switches of the respective BS tuners 27, 27a, . . . are shifted into the "OFF" position.
With each of the conventional power supply arrangements, since the selector switch for selecting one of the selectable switch positions is disposed on the back panel of each BS tuner, the selected position and function of the selector switch cannot easily be recognized. Inasmuch as the selector switch is generally not easy to handle and different power supply systems such as shown in FIGS. 1B and 1C may be employed, the selector switch of each BS tuner is held in the "OFF" position when the BS tuner is shipped from the factory. Not knowing that the selector switch is in the "OFF" position, the user of a brand-new BS tuner may complain about the failure of the BS tuner to reproduce video and audio signals through the AVTV.